40 CAPTURE OF INSECTS 



Petasia cassinea and Pcecilocampa populi have crowded 

 into my room. Of course, at such cool times of the year the 

 window must be kept shut, till the moths knock for admit- 

 tance. If at any time of the year a warm mist pervade the 

 air, there is almost a certainty of success. But should any 

 one be induced by this account to try the lamp, he must make 

 up his mind to experience more of unfavourable evenings than 

 favourable. There is, however, this advantage in my sedentary 

 plan of mothing, that it can be combined with reading or 

 writing ; and the intervals between the arrivals need not be 

 lost. 



Moths are extremely sensible of any keenness in the air ; 

 a north or east wind is very likely to keep them from ven- 

 turing abroad. Different species have different hours of flight. 

 Thus, on a mild and dark November evening, Pcecilocampa 

 populi will occupy from seven to ten o'clock, after which it 

 will make way for Petasia cassinea, which will fly till one or 

 two in the morning. I have, for experiment-sake, sat up 

 in the summer till three o'clock, when the whole heaven was 

 bright with the rising sun, and moths of various kinds have 

 never ceased arriving in succession till that time. Some of 

 them must come from a considerable distance. Scotophila 

 porphyrea, being a heath-moth, must come nearly a mile. 



Moths, like butterflies, have their peculiar modes of flight, 

 by which I can generally distinguish them on their entrance, 

 before I can see their colours. Some announce themselves 

 by a loud knock on the floor ; this is the case with Leiocampa 

 dictcea. Some ascend instantly to the ceiling; as Agrotis 

 corticea. Many, I might say the majority, pass the lamp 

 rapidly ; and this shews the comparative inutility of using a 

 lamp out of doors, where only those that loiter about it can 

 be taken. Some have a soft and gentle flight ; as, for instance, 

 Cosmia pyralina, one of my most welcome visitors, whose 

 entrance I am usually made aware of by seeing something drop 

 down on the table, as quick as hail, but as light as a fleece of 

 snow ; whilst, on the contrary, the conceited vagaries and 

 absurd violence of Clisiocampa neustria, are absolutely 

 amusing ; and cratcegi and populi are nearly as bad. It is not 

 the Nocturna a alone that come to me in the night, — many of 



a When I use the term, Nocturna, I do it in the enlarged sense of Latreille; 

 though Stephens prefers the term, Pomeridiana, for the families Ilepialidcc, 



